Latest Entries »

My current project is a robot transformer called Gyro. It is meant to transform from a good looking working car, into a good looking working biped. In theory, it seems easy, but I doubt it will be when I start building. The main idea is to have a 3 speed transmission, well a modified one at that to create an variable switch. Click here to see a picture of how it is supposed to be. The first motor spins the bottom array of gears, and the second uses a gear chain to move a transmission gear to transmit the power to gears with holes in the center, like the switch gears. Those gears then can be used to accomplish different tasks. As long as I’ve had an Nxt, I have wanted to build something like this, but only recently did I get a good idea of how to do so. The way it is meant to transform came from a video I watched a while back.

Gyro will only feature four places on the switch; one for the pneumatic transformations, one for driving, and one for any extra function I want to add. Instead of using 4 places on the switch just for driving and walking, I added a gear chain from one motor to keep spinning the switch, and when the switch reaches a certain position, it flips a two separate switches, changing the motor power from driving to walking, or vice-versa. The motor attached to the switch with the chain means that that switch will still have the ability to switch back. Click here to see a drawing of how this works. The top line goes to the switch, not illustrated, while the function switches are grey. Red represents a motor’s driving gear mode, while blue represents the walking system.

The leg walking system is composed of mainly a gear spinning a rack. As the rack is moved, the leg goes forward, but the lower part is anchored to the body, so it bends and lifts slightly off the ground. A closed shock absorber then pushes the foot to ground level, and the robot moves forward slightly. Next, the robot lowers the the foot an pulls it back in, and does the same thing with the other. Click here to see an illustration of the mechanism. This creates a perfect movement, yet there is a problem. This robot is supposed to transform into a car, and in the process bending it’s legs and folding them as to create the back of the car. However, the beam that makes the leg bend and the shock absorber pose a problem. I am still working on a way to make it be able to lock the shock absorber and make the beam be able to lock in a position when walking, yet be able to unlock and slide into itself when it is time to transform back into the car. I’m thinking of using pneumatics for this, yet I don’t know how far an extended pneumatic piston reaches. If it is not long enough, I may have to use linear actuators or modify the robot’s leg totally. If you have any suggestions, please leave a comment, and I will immediately when I receive it reply and tell you if it would work.